In numerous medical applications it is necessary to place a medical tube or lead within a patient.
U.S. Pat. No. 4,832,687 teaches a subcutaneous tunneling instrument and method for placing a subcutaneous catheter between two remote incisions in a patient. A subcutaneous tunnel is formed by pushing a rod having an elongated bullet-shaped tip removably threaded upon male threads disposed at the distal end of the rod into one incision and subcutaneously tunneling to and out through the second incision. The bullet-shaped tip is then removed from the distal end of the rod. The open end of a catheter is then slid over the male threads disposed at the distal end of the rod until the catheter abuts the rod. The distal end of the rod is then pulled back into the second incision and through the subcutaneous tunnel and through the first incision, and thereafter removing the open end of the catheter from the male threads at the distal end of the rod. This instrument and method requires appropriately sized male threads for different sized catheters. Further, there is no assurance that the catheter will stay on the male thread as it is being pulled by the rod through the body of a patient.
Another device and method is one comprising an extension passer, an obturator having a sharp end that serves as a tunneling tip, and a carrier. See for example, Medtronic Extension Passer 3555 Accessory Kit (by Medtronic, Inc. of Minneapolis, Minn., the assignee of the present invention). The tunneling tools of this kit are compatible with the Medtronic Neurological Extension Model 7499. In the Medtronic Extension Passer 3555 Accessory Kit, the extension passer is a hollow metal tube or shunt that the obturator can slide through. A handle is attached to the proximal end of the passer and allows the obturator to snap in place for tunneling. The obturator can also be removed and one extension (i.e., a lead) can be manually slid through the passer. The obturator is a narrow plastic cylinder with a sharp distal end that serves as a tunneling tip. The obturator slides through the extension passer and can be snapped in place into the extension passer's handle. The carrier is an attachment like an obturator, but with two distal carrier ports for extension connectors. Either one or two extension connectors can be attached and pulled through the extension passer.
One tunneling procedure using the Medtronic Extension Passer 3555 Accessory Kit comprises tunneling for a single extension without a carrier. In this procedure, with the obturator inserted in the extension passer, a tunnel is made from one incision to second incision or pocket within a patient. The obturator is then removed from the extension passer by unsnapping the end that is attached to the handle and sliding the obturator out from the extension passer at the second incision or pocket. The lead end of the extension is then inserted into the extension passer at the second incision or pocket and slid through the extension passer until it exits at the handle or until fully encompassed by the extension passer. The extension passer is then removed from the tunnel by pulling the handle away from the first incision, thereby leaving the extension in place as desired.
Another tunneling procedure using the Medtronic Extension Passer 3555 Accessory Kit comprises tunneling for a single extension with a carrier. In this procedure, with the obturator inserted in the extension passer, a tunnel is made from one incision to a second incision or pocket within a patient. With the extension passer in place, the obturator is then removed by unsnapping the end that is attached to the handle and sliding the obturator out from the extension passer at the second incision or pocket. Then the carrier is slid into the extension passer at the second incision or pocket until it exits at the handle. Then the proximal end of the carrier is snapped into the handle, leaving a single carrier port exposed at the distal end of the extension passer. The lead end of an extension is then inserted into the carrier port until it snaps into place. The extension passer, with the extension and carrier attached, is then pulled through the tunneled path to where the lead is to be anchored by pulling the handle away from the first incision. The extension passer and carrier are then completely removed from the body of the patient. The lead end of the extension is then removed from the carrier port. This method requires a separate extension passer, an obturator having a tunneling tip, and a carrier.
Another tunneling procedure using the Medtronic Extension Passer 3555 Accessory Kit comprises tunneling for two extensions for a dual-lead system. In this procedure, with the obturator inserted in the extension passer, a tunnel is made from one incision to second incision or pocket within a patient. With the extension passer in place, the obturator is then removed by unsnapping the end that is attached to the handle and sliding the obturator out from the extension passer at the second incision or pocket. Then the carrier is slid into the extension passer at the second incision or pocket until it exits at the handle, leaving both carrier ports exposed at the second incision or pocket. The lead end of an extension is then inserted into the first carrier port until it snaps into place. With the first extension attached to the distal end of the carrier, the proximal end of the carrier is pulled further through the extension passer handle. Then, the proximal end of the carrier is snapped into the handle such that the first carrier port is within the extension passer and the second carrier port remains exposed at the distal end of the extension passer. Then a second extension is placed into the second carrier port. With the extensions attached, the extension passer is then pulled through the tunneled path to where the leads are anchored. The second extension is then removed from the second carrier port. The carrier is then unsnapped from the handle and pushed forward to expose the first carrier port at the distal end. The first extension is then removed from the carrier. This method requires a separate extension passer, an obturator having a tunneling tip, and a carrier.